Fermenter Stir Plate

[sav]

I have just finished my stir plate for starters and I was anyone thought of 1 for the fermenter I would asume you go 240volt but the yeast would love you some one do it and I can say its was my idea.

sava

 

[razz]

Hi sav, I'm having a red wine after dinnner, what are you having?

 

[haysie]

Hi sav, I'm having a red wine after dinnner, what are you having?

#2 #7 #17 Vic Xmas Case Swap before dinner.....then> hmmm may try fit 16 rare earth magnets on each motor mower blade, turn it upside down, lay a copy of the financial review and watch all the bulls roar in.

 

[proudscum]

only if you really like oxidised beer.

 

[Kieren]

Wow, this thread went OT quickly.

I have had the same thought too, ferment stir plate would be great for those really flocculant yeasts you need to rouse back into suspension. Though not being great at all things electronic I have not entertained the idea of building something myself.

Would love to see an off the shelf bit of gear. A bit of research would need to be done to see how successful it would be though.

You wouldn't need to create a massive whirlpool, just a quirk stir every now and then.

 

[haysie]

Wow, this thread went OT quickly.

Afterall, it was a ripper new piece of read wasnt it.

 

[Phoney]

What about a giant blender for a fermenter?

 

[Online Brewing Supplies]

It in a way has been done and still is. The fermenting wort is roused by and external pump and the yeast is kept in suspension resulting in better attenuation and faster turn around. I think it was first done in the NZ land. Goggle continuous fermentation.
GB

 

[felten]

yorkshire square?

 

[sav]

Afterall, it was a ripper new piece of read wasnt it.

If your a cock

 

[Yob]

is it just the threads im reading or are alot of these threads ending in someone being called a cock lately? :blink: .. for christ sake theres at least one whole language out there people.. probably more... Personally I prefer Thai curses...

yet man for one is a corker... (Mutha Fuc*#r)

...jeez at least it would be amusing trying to find out what some cok just called you

 

[Thirsty Boy]

There are flavour implications for continuously stirring fermenters.... Duh that not very many commercial brewers do it, even though it can result in faster, more highly attenuated fermentations.

It's not like it can't or shouldn't be done, its just that the results will be different in a number of ways to a non agitated ferment.

I can sort of see the potential usefulness for highly flocculent strains... Stirrer on a timer, comes on for a minute or two every hour maybe???

It might be easier just to build a lazy Susan to sit your fermenter on though, give it a spin every now and again, motorized if you like your gadgets?

I think a fermenter sized stir plate would be kinda cool to see though and I'd like to see it if anyone does build one.

 

[SpillsMostOfIt]

I just had a vision of a fermenter sitting in a top-loading washing machine.

 

[beerbrewer76543]

I just had a vision of a fermenter sitting in a top-loading washing machine.

Getting some cock?

 

[sav]

Or maybe it could be used to aerate your wort before pitching?

 

[jonocarroll]

only if you really like oxidised beer.

Thanks for the opportunity I've been looking for to point this out - it's been coming up a few times lately...

Why do people keep suggesting that a volume of liquid sealed with positive pressure in a CO₂ environment (normal air having been expelled, being lighter than CO₂) will oxidise (or will dissolve oxygen if you wish to be pedantic) if you shake it? Seems quite odd to me.

Anyway, given that the main reasons for a stirbar are assumed to be: 1) keeping the yeast in suspension, and 2) assisting in driving off CO₂ then I can't see why a good shake won't do the trick. Automating this might be as simple as some sort of vibrating plate under the fermenter that kicks off every so often and shakes the yeastcake back into the path that the krausen's taking.

Getting a stirbar to start rotating from a cold start in an inch of yeastcake might take some serious magnetism.

 

[schooey]

Automating this might be as simple as some sort of vibrating plate under the fermenter that kicks off every so often and shakes the yeastcake back into the path that the krausen's taking.

What about one of these?

Cautiuon maybe ****

Seriously... fully waterproof, remote controlled...You could probably rig it to a timer, what more do you want?

 

[Thirsty Boy]

Yu are right about the "main" things that the stir bar does. Driving off CO2 and keeping the yeast up and agitated is probably the biggest thing.

BUT

In the initial stages, when yeast is absorbing oxygen as a nutrient (not for respiration) - there is very little actual CO2 evolution and a stir plate keeps the levels of dissolved O2 in the wort nice and high up until the point where there is.

Also, most guides I have read about making stir plate starters, and how everyone who i have seen make a stirplate starter does it, suggest you don't use something that will provide a positive seal like an airlock, but instead you use a bit of foil scrunched over your flask. A loose enough cover so that oxygen is still able to diffuse into the flask and balance the partial pressures.

So a stir plate is mainly about oxygen in the initial stages of a starter and in the later stages once co2 is being produced in volumes high enough to push out the oxygen, it is about knocking the Co2 out of solution and about physically keeping the yeast up in suspension.

A fermenter sized stir plate naturally wouldn't oxidize the beer, for the same reasons... The oxygen is good for the beer when its going to be available, and not there when its not going to be good. If your fermenter was poorly sealed, you would probably want to turn it off if/when your fermentation slowed down to the point where little co2 was being produced and oxygen could start to diffuse in again.

Or - I misunderstand things. Which is always possible.

 

[Bizier]

It might be easier just to build a lazy Susan to sit your fermenter on though, give it a spin every now and again, motorized if you like your gadgets?

I got a lazy susan from Ikea for about $15 or so from memory for this purpose. Caveat emptor: absolutely none of them are remotely close to swivelling at the centre of the platform. I was going to run a motor against the edge to drive it with friction, but it waaaay too sloppy. Still useful for manual rousing.

I like your idea Schooey. If my beer starts tasting fishy, I'll blame isinglass.

 

[jonocarroll]

What about one of these?

I considered making the joke myself, but thought I'd try to keep the civility of this thread at a level at least equal to where it started.

Also, most guides I have read about making stir plate starters, and how everyone who i have seen make a stirplate starter does it, suggest you don't use something that will provide a positive seal like an airlock, but instead you use a bit of foil scrunched over your flask. A loose enough cover so that oxygen is still able to diffuse into the flask and balance the partial pressures.

This is the argument I get each time I discuss the topic - and it's come to argument - but I'm yet to be convinced that even a good vortex is pulling in a significant amount of oxygen through the neck of a conical flask sealed loosely with foil. If that WERE true, then surely I could test it by simply replacing the foil with some sort of device that indicates the direction of pressure... say, an S-bend airlock, perhaps.

Strangely, when I attach my airlock to each of my starters, I invariably get bubbling, even at the start of yeast production. Go figure.

I have more trouble believing that against the net pressure (or even, for arguments sake, in the case of zero net pressure) diffusion past loosely scrunched foil is leading to a viable source of oxygen, as opposed to a lowered partial pressure of oxygen in the flask, but that said I'll gladly accept good scientific evidence to the contrary.